As I was driving after a certain speed, I started noticing a noise, next day started to check underneath the vehicle and found this. Anyone know where I can find a replacement for this or what this part is called? It seems to be protecting the brake lines.

 

You're correct as that looks like the plastic cover for the fuel and brake lines. With how old our cars are, they start to get brittle and crack even if the car hasn't ever bottomed out. They are costly at the dealer...I think around $400 or so last I looked. You can try finding a used pair (its two parts a front and a back section).

 

Any idea what it might be called?